Romney won’t “rule” at all.
If nominated, he will lose to Obama. Obama is licking his chops in glee, he will run rings around Mitt. Axelrod has already prepared a five-foot thick file on Romney.
After all, Mitt had already lost to the guy who lost to Obama in 2008.
Romney would be Obama’s dream Republican contender. This short video will give you a flavor of how a debate between them might play out.